Investigating Longevity of Corrosion Inhibitors and Performance of Deicer Products Under Storage or After Pavement Application

This study evaluated the longevity of corrosion inhibitors and the performance of inhibited deicer products under storage or after pavement application. No significant degradation of corrosion inhibitor or loss of chlorides was seen during the months of field storage. The fate and transport of the inhibitors differed from those of the chlorides, in which dilution by precipitation and likely wicking of the deicer into the pavement and the top snow layer contributed to the loss of inhibitor and chlorides. The accelerated UV-degradation lab study found little degradation of GLT and FreezGard inhibitors but significant degradation of CCB inhibitor. While these inhibitors demonstrated their effectiveness in corrosion inhibition, they showed no side benefits in deicer performance. No significant difference in anti-icing performance was observed between the three liquid deicers during the two storm events. All three liquid deicers worked effectively for anti-icing applications under the investigated conditions. It is unnecessary to implement any mixing for the liquid deicer tanks, other than immediately prior to the use of the liquid deicers to ensure uniform composition and minimize stratification. Without dilution by precipitation (the black ice event), the percent of chloride recovered from the pavement by day 4 was approximately 30%, 20%, and 50% for NaCl+GLT, CCB, and FreezGard respectively. Up to 80% of the CCB inhibitor was recovered from the pavement 4 days after the deicer application. While such residuals could be washed away by precipitation, their presence on the pavement could potentially be measured and considered when re-applying chemicals for snow and ice control. This project revealed that the relative corrosivity of deicer solutions on the field pavement differed from that in the lab.